### Function

# GLib OptionArgFunc

#### Declaration

    gboolean
    (* GOptionArgFunc) (
      const gchar* option_name,
      const gchar* value,
      gpointer data,
      GError** error
    )

#### Description [src]

The type of function to be passed as callback for `G_OPTION_ARG_CALLBACK` options.

#### Parameters

`option_name`

  Type: `const gchar*`

  The name of the option being parsed. This will be either a single dash followed by a single letter (for a short name) or two dashes followed by a long option name.

  The data is owned by the caller of the function.
  The value is a NUL terminated UTF-8 string.

`value`

  Type: `const gchar*`

  The value to be parsed.

  The data is owned by the caller of the function.
  The value is a NUL terminated UTF-8 string.

`data`

  Type: `gpointer`

  User data added to the `GOptionGroup` containing the option when it was created with g_option_group_new().

  The argument can be `NULL`.
  The data is owned by the caller of the function.

`error`

  Type: `GError **`

  The return location for a recoverable error.

  The argument can be `NULL`.
  If the return location is not `NULL`, then you must initialize it to a `NULL` `GError*`.
  The argument will be left initialized to `NULL` by the function if there are no errors.
  In case of error, the argument will be set to a newly allocated `GError`; the caller will take ownership of the data, and be responsible for freeing it.

#### Return value

Type: `gboolean`

`TRUE` if the option was successfully parsed, `FALSE` if an error occurred, in which case `error` should be set with g_set_error().